Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386

[Igor Mammedov]

On Fri, 10 Jan 2014 10:35:14 -0500
"Gabriel L. Somlo" <address@hidden> wrote:

> On Fri, Jan 10, 2014 at 01:37:14PM +0100, Paolo Bonzini wrote:
> > Il 09/01/2014 22:44, Gabriel L. Somlo ha scritto:
> > > 1. hardcode "IRQNoFlags(){2, 8}" and require -no-hpet to prevent XP
> > >    from bluescreening. Basically, this means we don't support XP on
> > >    a VM where HPET is enabled.
> > > 
> > > 2. conditionally insert "IRQNoFlags(){2, 8}" if _OSI("Darwin") returns
> > >    0xFFFFFFFF, which is only necessary if we want to run OS X on piix+smp
> > >    (all other combinations of (piix vs. q35) x (up vs.  smp) work fine
> > >    already).
> > 
> > _OSI is bad, but (1) is worse.
> 
> Agreed.
> 
> > > I still don't get why on real hardware where the HPET has
> > > "IRQNoFlags(){2, 8}" in its _CRS method XP seems to be OK...
> > 
> > My laptop has this:
> >
> > [...] 
> >
> >                     Name (BUF0, ResourceTemplate ()
> >                     {
> >                         Memory32Fixed (ReadOnly,
> >                             0xFED00000,         // Address Base
> >                             0x00000400,         // Address Length
> >                             _Y27)
> >                     })
> >                     Method (_CRS, 0, Serialized)  // _CRS: Current Resource 
> > Settings
> >                     {
> >                         CreateDWordField (BUF0, 
> > \_SB.PCI0.LPC.HPET._Y27._BAS, HPT0)  // _BAS: Base Address
> >                         Store (\HPET, HPT0)    // HPET comes from a table 
> > that BIOS fills in reserved memory
> >                         Return (BUF0)
> >                     }
> >                 }
> > 
> > so no IRQs, and my workstation is similar.  They are respectively from
> > Lenovo and Fujitsu.  Looks like an Apple quirk.
> 
> Hmmm, I could have sworn I saw IRQNoFlags on one of my old Dell
> laptops (Dell Latitude D630), but I just had another look and it's
> not there, so I was clearly misremembering that !
> 
> I think you're right, of all the hardware I currently have access to,
> only the various Apple machines have IRQNoFlags in HPET._CRS !
> 
> Given that, I'm starting to feel better and better about using _OSI().
> 
> Michael: regarding your comment about "ConcatenateResTemplate" not
> being supported by XP: Can I safely assume that as long as it's always
> on the branch NOT taken by XP, we're OK having it in there ? E.g.,
there is harder route to get a clue why XP BSODs,
one can use AMLI debugger to see what is happening in XP on boot
http://msdn.microsoft.com/en-us/library/windows/hardware/ff537808%28v=vs.85%29.aspx
that was how I found out about not supported ConcatenateResTemplate first.

> 
>     if _OSI("Darwin") then
>       ConcatenateResTemplate...
>     else
>       stuff_that_XP_cares_about
> 
> Once I have that sorted out, I'll send a patch.
> 
> Thanks,
> --Gabriel